Composite adsorbents for purifying hydrocarbon streams

ABSTRACT

Applicant has developed an improved adsorbent useful in removing contaminants from various hydrocarbon streams. The adsorbent contains a zeolite, an alumina and a metal component. The metal component (Madd) is present in an amount at least 10 mole % the stoichiometric amount of metal (M) (expressed as the oxide) needed to balance the negative charge of the zeolite lattice. In a specific application an adsorbent comprising zeolite X, alumina and sodium is used to purify an ethylene stream in order to remove CO 2 , H 2 S, methanol, and other S— and O— containing compounds.

FIELD OF THE INVENTION

[0001] This application relates to an adsorbent which comprises azeolite, an alumina component and a metal component e.g. sodium in anamount at least 10% of the zeolite's ion exchange capacity. This newadsorbent is used to remove contaminants from hydrocarbon streams, e.g.removing CO₂, CO3, H₂ 3, AsH₃, methanol, mercaptans and other S- orO-containing organic compounds from ethylene, propylene, C₃-C₄hydrocarbon products and other lights hydrocarbon streams.

BACKGROUND OF THE INVENTION

[0002] Solid adsorbents are commonly used to remove contaminants fromhydrocarbon streams such as olefins, natural gas and light hydrocarbonfractions. Since these streams can contain different contaminants, morethan one adsorbent or adsorbent bed are needed to sufficiently purifythe stream so that it can be used in the desired process. Contaminantswhich can be present in these streams include H₂O, CO, O₂, CO₂, COS,H₂S, NH₃, AsH₃, PH₃, Hg, methanol, mercaptans and other S- orO-containing organic compounds.

[0003] However, while various adsorbents can remove one or morecontaminant, they can also remove and/or promote reactions of thedesired hydrocarbon. For example, faujasite type zeolites, e.g. zeolite13X, are good adsorbents for sulfur and oxygenate compounds but they arealso good adsorbents for olefins which results in high temperature risethat can cause run-away reactions. Additionally, owing to the zeolite'sresidual surface reactivity reactions such as oligomerization andpolymerization can occur during regeneration. This leads to fouling andperformance deterioration.

[0004] In attempts to remedy this problem, there are reports in the artwhere zeolites have been mixed with alumina. U.S. Pat. No. 4,762,537discloses the use of an adsorbent comprising zeolite Y and alumina toremove HCl from a hydrogen stream. In U.S. Pat. Nos. 4,686,198 and4,717,483 it is disclosed that a mixture of alumina and sodium Y zeolitecan remove ammonia sulfides and organic impurities from waste water. Thesodium Y zeolite contains at least 12.7 wt. % Na₂O. The same adsorbentis also used to reduce the acidity and moisture content of usedorganophosphate functional fluids, see U.S. Pat. No. 4,751,211. The useof alumina with alkali or alkaline earth metal for removing HCl andother contaminants is disclosed in U.S. Pat. No. 6,013,600.

[0005] Applicant has developed an improved adsorbent which can removemultiple contaminants from various hydrocarbon streams. Surprisinglythese contaminants can be removed with only a small temperature rise andthe adsorbent has increased stability upon multiple regenerations. Thisadsorbent comprises a zeolite, alumina and a metal component (Madd)which is present in an amount of at least 10 mole % of thestoichiometric amount of metal (expressed as the oxide) needed tocompensate for the negative charge of the zeolite lattice.

SUMMARY OF THE INVENTION

[0006] This invention relates to a solid shaped adsorbent, a process forpreparing the adsorbent and a process for removing contaminants from ahydrocarbon stream using the adsorbent. Accordingly, one embodiment ofthe invention is a solid shaped adsorbent for purifying hydrocarbonstreams comprising an alumina component, a zeolite component and a metalcomponent selected from the group consisting of alkali metals, alkalineearth metals and mixtures thereof, the metal component present in anamount of at least 10 mole % of the stoichiometric amount of metalneeded to compensate for the negative charge of the zeolite lattice,expressed as the oxide.

[0007] Another embodiment of the invention is a process for preparing asolid shaped adsorbent for purifying hydrocarbon streams comprising analumina component, a zeolite component and a metal component selectedfrom the group consisting of alkali metals, alkaline earth metals andmixtures thereof, the metal component present in an amount of at least10 mole % of the stoichiometric amount of metal needed to compensate forthe negative charge of the zeolite lattice, expressed as the oxide.

[0008] The process comprises forming a shaped article by combining analumina component, a zeolite component and a metal component precursorin any order to form a shaped article, curing the shaped article atcuring conditions to give a cured shaped article and activating thecured article at activation conditions to give the solid shapedadsorbent.

[0009] Yet another embodiment of the invention is a process for removingcontaminants from hydrocarbon streams comprising contacting the streamwith the solid shaped adsorbent described above at adsorption conditionsto remove at least a portion of at least one contaminant.

[0010] These and other objects and embodiments will become clearer aftera detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0011] Applicant's invention comprises a solid shaped adsorbent, aprocess for preparing the adsorbent and purification processes using theadsorbent. With regard to the solid shaped adsorbent, one necessarycomponent is an activated alumina. Activated aluminas include aluminashaving a surface area usually greater than 100 m²/g and typically in therange of 100 to 400 m²/g. Further, the activated alumina powder ispreferably obtained by rapid dehydration of aluminum hydroxides, e.g.,alumina trihydrate of hydrargillite in a stream of hot gasses or solidheat carrier. Dehydration may be accomplished in any suitable apparatususing the stream of hot gases or solid heat carrier. Generally, the timefor heating or contacting with the hot gases is a very short period oftime, typically from a fraction of a second to 4 or 5 seconds. Normally,the temperature of the gases varies between 400° and 1000° C. Theprocess is commonly referred to as flash calcination and is disclosed,for example in U.S. Pat. No. , 2,915,365, incorporated herein byreference. However, other methods of calcination may be employed.

[0012] The activated aluminas suitable for use in the present inventionhave a median particle size in the range of 0.1 to 300 microns,preferably 1 to 100 microns and typically 1 to 20 microns. In certaininstances, it may be desirable to use aluminas with a median particlesize of 1 to 10 microns. The alumina may be ground to the desiredparticle size before or after activation. The activated aluminatypically has an LOI (loss on ignition) in the range of about 5 to 12%at a temperature of 200° to 1000° C.

[0013] One source of activated alumina is gibbsite which is one form ofalumina hydrate derived from bauxite using the Bayer process. However,alpha alumina monohydrate, pseudoboehmite or the alumina trihydrate maybe used if sufficiently calcined. Other sources of alumina may also beutilized including clays and alumina alkoxides.

[0014] Another necessary component of the present invention is azeolite. Zeolites are crystalline aluminosilicate compositions which aremicroporous and which have a three-dimensional oxide framework formedfrom comer sharing AlO₂ and SiO₂ tetrahedra. Zeolites are characterizedby having pore openings of uniform dimensions, having a significant ionexchange capacity, and being capable of reversibly desorbing an adsorbedphase which is dispersed throughout the internal voids of the crystalwithout significantly displacing any atoms which make up the permanentzeolite crystal structure. The zeolites which can be used in the presentinvention are those which have a pore opening of about 5 to about 10 Å.

[0015] In general, the zeolites have a composition represented by theempirical formula:

M_(2/n)O:Al₂O₃: bSiO₂

[0016] M is a cation having a valence of “n” and “b” has a value ofabout 2 to about 500. Preferred zeolites are those that have aSiO₂/Al₂O₃ ratio of about 2 : 1 to about 6 : 1 and/or those having thecrystal structure of zeolite X, faujasite, zeolite Y, zeolite A,mordenite, beta and ferrierite. Especially preferred zeolites arezeolites X, Y and A.

[0017] Preparation of these zeolites is well known in the art andinvolves forming a reaction mixture composed of reactive sources of thecomponents which mixture is then hydrothermally reacted to form thezeolite. Specifically, the synthesis of zeolite Y is described in U.S.Pat. Nos. 3,130,007 and 4,503,023 and that of zeolite X in U.S. Pat.Nos. 2,883,244 and 3,862,900 the disclosures of which are incorporatedby reference.

[0018] Although the synthesis of zeolites, and zeolites X and Y inparticular, are well known, a brief description will be presented herefor completeness. Reactive sources of M include the halide and hydroxidecompounds of alkali or alkaline earth metals such as sodium chloride,sodium hydroxide, potassium hydroxide, etc. Aluminum sources include butare not limited to boehmite alumina, gamma alumina and solublealuminates such as sodium aluminate or tetraethylammonium aluminates.Finally, silicon sources include, silica, silica hydrosol, silicic acid,etc.

[0019] The reactive sources are combined into a reaction mixture whichhas a composition in terms of mole ratios of the oxides of: SiO₂/Al₂O₃ = 8 to 12 M₂O/Al₂O₃ = 2.5 to 4   H₂O/M₂O = 120 to 180

[0020] and the mixture is then reacted to form the zeolite.

[0021] As synthesized, the zeolites will contain “M” metals in thechannels and/or pores. The function of these metal cations is to balancethe negative charge of the zeolite lattice. Since these cations are notpart of the framework, they are exchangeable and are said to occupyexchange sites. The amount of metal cations present in the zeolite isreferred to as the stoichiometric amount or the maximum ion exchangecapacity of the zeolite. This amount is usually expressed in moles.

[0022] Since the metal cations initially present in the zeolite areexchangeable they can be exchanged for other (different) alkali metals,alkaline earth metals, hydronium ions, ammonium ions or mixturesthereof. If the zeolite to be used contains partially or completelyhydronium or ammonium ions, then these ions must be fully exchanged withalkali metals, alkaline earth metals or mixtures thereof, either beforeor during the preparation of the composite adsorbent.

[0023] Another necessary component of the shaped adsorbent of thisinvention is a metal component (Madd) selected from the group consistingof alkali, alkaline earth metals and mixtures thereof. This metalcomponent (Madd) is in addition to the metal cation (M) present in theexchange sites of the zeolite. Additionally the Madd metal can be thesame or different than the M metal. For example, the M metal in azeolite can be potassium whereas the Madd can be sodium.

[0024] Specific examples of Madd include but are not limited to sodium,potassium, lithium, rubidium, cesium, calcium, strontium, magnesium,barium, zinc and copper. The source of the (metal component precursor)can be any compound which at activation conditions, (see infra)decomposes to the metal oxide. Examples of these sources are thenitrates, hydroxides, carboxylates, carbonates and oxides of the metals.The shaped adsorbent can be prepared by combining the three componentsin any order and forming into a shaped article although not necessarilywith equivalent results.

[0025] In one method, the alumina, zeolite and an aqueous solution ofthe desired metal compound are mixed and formed into a shaped article.For example, gamma alumina, zeolite X and a solution of sodium acetatecan be combined into a dough and then extruded or formed into shapessuch as pellets, pills, tablets or spheres (e.g. by the oil drop method)by means well known in the art. A preferred method of formingsubstantially rounded shapes or bodies involves the use of a pannodulizer. This technique uses a rotating pan or pan nodulizer ontowhich is fed the alumina component, zeolite component and a solution ofthe metal component thereby forming substantially rounded articles orbodies.

[0026] Another method of forming the shaped article is to mix powders ofthe alumina, zeolite and metal compound followed by formation ofpellets, pills, etc. A third method is to combine the alumina andzeolite components (powders), form them into a shaped article and thenimpregnate the shaped article with an aqueous solution of the metalcompound. The forming step is carried out by any of the means enumeratedabove.

[0027] In preparing a solution of the desired metal compound, it ispreferred to adjust the pH to a value from about 7 to about 14, morepreferably from about 12 to about 14 and most preferably from about 12.7to about 13.8. The pH of the solution is controlled by adding theappropriate amount of the desired metal hydroxide. For example, ifsodium is the desired metal, sodium acetate can be used to form theaqueous solution and the pH is then adjusted using sodium hydroxide.

[0028] Having obtained the shaped articles, they are cured or dried atambient temperature up to about 200° C. for a time of about 5 minutes toabout 25 hours. The shaped articles can be cured in batches e.g. bins ortrays or in a continuous process using a moving belt. Once the shapedarticles are cured, they are activated by heating the cured articles ata temperature of about 275° C. to about 600° C. for a time of about 5 toabout 70 minutes. The heating can be done with the articles in a movingpan or in a moving belt where the articles are direct fired to providethe finished solid adsorbent.

[0029] The relative amount of the three components can vary considerablyover a wide range. Usually the amount of alumina varies from about 40 toabout 90% of the adsorbent and the amount of zeolite varies from about 5to about 55 wt. % of the adsorbent. The amount of metal component, Madd,can also vary considerably, but must be present in an amount equal to atleast 10% of the stoichiometric amount of the metal cation, M, presentin the exchange sites of the zeolite. For practical reasons, the maximumamount of Madd should be no more than 50% of the stoichiometric amountof M. In absolute terms, it is preferred that the amount of Madd bepresent from about 0.015 to about 0.08 moles of Madd per 100 gm ofadsorbent. The amounts of M and Madd are reported or expressed as theoxide of the metal, e.g. Na₂O.

[0030] The finished adsorbent can now be used to remove contaminantsfrom various hydrocarbon streams. The streams which can be treatedinclude but are not limited to hydrocarbon streams, especially thosecontaining saturated and/or unsaturated hydrocarbons. Olefin stream suchas ethylene, propylene and butylenes can be especially treated using theinstant adsorbent. These streams will contain one or more of thefollowing contaminants: H₂O, CO, O2, CO₂, COS, H₂S, NH₃, AsH₃, PH₃, Hg,methanol, mercaptans and other S- or O-containing organic compounds.

[0031] The hydrocarbon streams are purified by contacting the streamwith the solid adsorbent at adsorption conditions. The contacting can becarried out in a batch or continuous process with continuous beingpreferred. The adsorbent can be present as a fixed bed, moving bed orradial flow bed with fixed bed being preferred. When a fixed bed isused, the feed stream can be flowed in an upflow or downflow direction,with upflow being generally preferred for liquid feeds. If a moving bedis used the feed stream flow can be either co-current orcounter-current. Further, when a fixed bed is used, multiple beds can beused and can be placed in one or more reactor vessel. Adsorptionconditions include a temperature of about ambient to about 80° C., apressure of about atmospheric to about 100 atm. (1.01×10⁴ kPa) and acontact time which depends on whether the hydrocarbon stream is a liquidor gaseous stream. For a liquid stream the contact time expressed interms of liquid hourly space velocity (LHSV) is from about 0.5 to about10 hr⁻¹, while for a gaseous stream, the gas hourly space velocityvaries from about 500 to about 10,000 hr⁻¹.

[0032] After a certain amount of time, which time depends on theconcentration of contaminants, the size of the bed and the spacevelocity, the adsorbent will be substantially spent, i.e. has adsorbedan amount of contaminant(s) such that the level of contaminant in thepurified stream is above an acceptable level. At this time, theadsorbent is removed and replaced with fresh adsorbent. The spentadsorbent can be regenerated by means well known in the art and thenplaced back on service. In a typical regeneration procedure, theadsorbent is first drained and depressurized followed by a cold purgewith an inert stream. Next, a warm purge in a downflow direction at80-150° C. removes the retained hydrocarbons from the bed. Finally, thetemperature is slowly raised to 280-320° C. and held there for at least2 hours and then cooled to ambient temperature.

[0033] The following examples are set for in order to more fullyillustrate the invention. It is to be understood that the examples areonly by way of illustration and are not intended as an undue limitationon the broad scope of the invention as set forth in the appended claims.

EXAMPLE 1

[0034] Balls containing alumina, zeolite 13X and sodium where preparedas follows. A rotating pan device was used to continuously form beads bysimultaneously adding activated alumina powder (AP) and zeolite 13Xpowder (Z) while spraying the powders with a sodium acetate solution(NaAc). The mass ratio (on a volatile free basis) was 1.0 AP:0.23 Z:0.04NaAc. Water was added as needed to keep the sodium acetate dissolved andto provide for sufficient agglomeration. The pH of the NaAc solution wasadjusted to 13.3 by adding a NaOH solution. The balls, which had a sizedistribution from 1.2 to 4 mm were cured at 60-80° C. for three hoursusing a heated belt. Finally, the cured beads were activated in an ovenat about 450° C. for one hour. The amount of each component (wt. %) on avolatile free basis was found to be 78.7% AP; 18.1% Z; 3.2% Na₂O.

EXAMPLE 2

[0035] The procedure set forth in Example 1 was used to prepare ballsexcept that the mass ratio of AP:Z:NaAc was 1.0:0.55:0.035. The amountof each component (wt. %) on a volatile free basis was found to be 63.1%AP; 34.7% Z; 2.2% Na₂O.

EXAMPLE 3

[0036] The procedure set forth in Example 1 was used to prepare ballsexcept the mass ratio of AP:Z:NaAc was 1.0:0.37:0.05. The amount of eachcomponent (wt. %) on a volatile free basis was found to be 70.4% AP;26.1% Z; 3.5% Na₂O.

EXAMPLE 4

[0037] The procedure in Example 3 was used to prepare balls except thatwater was used instead of NaAc. The amount of each component (wt. %) ona volatile free basis was found to be 72.9% AP; 26.9% Z; 0.2% Na₂O.

EXAMPLE 5

[0038] The process of Example 1 was carried out except that zeolite NaY(obtained from UOP LLC) was used instead of zeolite 13 X and the ratiowas 1AP : 0.37Z. The amount of each component (wt. %) on a volatile freebasis was found to be 72.9% AP; 26.9% Z; 0.2% Na₂O.

EXAMPLE 6

[0039] In a rotating container there were placed 500g of the balls fromExample 5 and 200g of a 4.6 wt. % sodium acetate solution. The ballswere cured by rotating the closed container for one hour and thenactivated as per Example 1. The amount of each component (wt. %) on avolatile free basis was found to be 72.36% AP; 26.7% Z; 0.94% Na₂O.

EXAMPLE 7

[0040] Balls were prepared as in Example 6 except that a solutioncontaining 10.9 wt. % sodium acetate was used. The amount of eachcomponent (wt. %) on a volatile free basis was found to be 71.65% AP;26.44 Z; 1.91% Na₂O.

EXAMPLE 8

[0041] Balls were prepared as in Example 6 except that a solutioncontaining 17.1% sodium acetate was used. The amount of each component(wt. %) on a volatile free basis was found to be 70.9% AP; 26.18% Z;2.88% Na₂O.

EXAMPLE 9

[0042] Samples from Examples 1-7 were tested for CO₂ and propyleneadsorption using a McBain balance. CO₂ is used to measure adsorption ofacidic gases, while propylene measures the ability to adsorb organiccompounds. About 30mg of each sample was heated in flowing helium to400° C. at a rate of 25° C./min. held there for about 45 min. and thencooled (under helium to room temperature). Adsorption was carried out byflowing a stream of either 1% propylene in helium or 1.5% CO₂ in heliumover the sample at 38° C. for 20 minutes and measuring the weightchange. The results are presented in Table 1 TABLE 1 AdsorptionCapacity* of Various Adsorbents Na₂O Na₂O mol/100/gm mol/100 gm SampleID total added Propylene CO₂ Example 1 0.108 0.052 2.57 3.9 Example 20.147 0.035 4.06 4.8 Example 3 0.140 0.056 3.22 4.3 Example 4 0.0890.003*** 3.3 3.5 Example 5 0.058 none 2.37 0.78** Example 6 0.071 0.0122.29 0.85** Example 7 0.087 0.028 2.2 0.99** Example 8 0.103 0.044 2.221.1*

[0043] Examples 1-4 used zeolite X while Examples 5-8 used zeolite Y.For both zeolites it is observed that the propylene adsorption isaffected very little by the addition of sodium, but the CO₂ adsorptionimproves considerably.

EXAMPLE 10

[0044] Samples from Examples 1-4 were tested for surface reactivityusing 1-hexene as the probe molecule. About 70mg from each sample (as apowder) was placed in a tubular flow reactor placed in a furnace. Eachsample was activated at 350° C. for 1 hour in helium and then cooled to150° C. Next a feed stream prepared by bubbling helium through asaturator containing 1-hexene was flowed through the catalyst at a rateof 20cc/min, while measuring the hexene conversion at varioustemperatures in the temperature range of 150° C. to 500° C. Hexeneconversion was measured using a gas chromatograph. The major product ofthis reaction at low conversion were 2-hexene and 3-hexene. Formation ofmethyl branched isomers and cracking products occurred at highconversion. The overall conversion of 1-hexene are shown in Table 2.TABLE 2 +HC,1/ 1-hexene Conversion (%) of Various Adsorbents Sample ID200° C. 250° C. 350° C. Example 1 0 0 7.4 Example 2 0 0 15.5 Example 3 00 7.5 Example 4 18.8 57.8 83.4

[0045] This data clearly shows that an alumina/zeolite adsorbent withoutadditional sodium (Example 4) has much more reactivity for 1-hexeneconversion. Since the adsorbents are regenerated in the same temperaturerange as the range in Table 2, the low catalytic activity of theadsorbents of Examples 1-3 indicates that the presence of sodium (at theabove levels) would strongly reduce the likelihood of coking or run-awayreaction when the above adsorbents undergo regeneration.

[0046] Samples from Example 5-8 were tested as above and the results arepresented in Table 3. TABLE 3 1-hexene Conversion (%) of VariousAdsorbents Sample ID 200° C. 250° C. 300° C. Example 5 45.2 79.4 89Example 6 5.9 38.5 71.3 Example 7 0.7 6.4 24.5 Example 8 0.2 — 10.8

[0047] The results in Table 3 show the same performance using zeolite Yas shown in Table 2 using zeolite X. That is the presence of additionalsodium greatly reduces the reactivity of the adsorbent.

EXAMPLE 11

[0048] A series of zeolites were combined with alumina (AP) and sodiumacetate powders and thoroughly mixed. A small sample was transferred toa microbalance, activated in a helium flow at 700° C. and then cooled to38° C. Propylene adsorption measurements were carried out as per Example9 and the results presented in Table 4. TABLE 4 Effect of Components ofPropylene Adsorption Propylene Sample Composition (wt. %) Adsorption IDAP NaY 13X 3A Na₂O (g/100 g) A 72.7 27.3 3.29 B 69.7 26.2 4.1 2.66 C25.4 70.6 4.0 1.33 D 77.1 22.9 2.42 E 74.7 22.2 3.2 2.12 F 21.2 74.6 4.20.84

[0049] The results in Table 4 show that the addition of sodium does notaffect propylene adsorption very much (compare samples A vs. B and D vs.E). However, when the adsorbent contains only zeolites, additionalsodium lowers propylene adsorption (samples A vs. C and D vs. F). Thisshows the function of the alumina.

What is claimed is:
 1. A solid shaped adsorbent for purifyinghydrocarbon streams comprising an alumina component, a zeolite componentand a metal component (Madd), the metal component present in an amountat least 10 mole % of the stoichiometric amount of metal (M) needed tocompensate for the negative charge of the zeolite lattice, expressed asthe oxide.
 2. The adsorbent of claim 1 where the zeolite is selectedfrom the group consisting of zeolite X, zeolite Y, zeolite A andmixtures thereof.
 3. The adsorbent of claim 2 where the zeolite iszeolite X.
 4. The adsorbent of claim 1 where the metal component (Madd)is an alkali metal selected from the group consisting of sodium,potassium, lithium, rubidium, cesium and mixtures thereof.
 5. Theadsorbent of claim 4 where the metal component is sodium.
 6. Theadsorbent of claim 1 where the zeolite is present in an amount fromabout 5 to about 55 wt. % of the adsorbent.
 7. The adsorbent of claim 1where the metal component (Madd) is present in an amount from about0.018 to about 0.08 moles of metal as the oxide per 100 g of adsorbents.8. A process for preparing a solid shaped adsorbent for purifyinghydrocarbon streams comprising an alumina component, a zeolite componentand a metal component (Madd) selected from the group consisting ofalkali metals, alkaline earth metals and mixtures thereof, the metalcomponent present in an amount at least 10 mole % of the stoichiometricamount of metal (M) needed to compensate for the negative latticeexpressed as the oxide charge of the zeolite the process comprisesforming a shaped article by combining an alumina component a zeolitecomponent and a metal component precursor in any order to form a shapedarticle, curing the shaped article at curing condition's to give a curedshaped article and activating the cured article at activation conditionsto give the solid shaped adsorbent.
 9. The process of claim 8 where thezeolite component is selected from the group consisting of zeolite X,zeolite Y, zeolite A and mixtures thereof.
 10. The process of claim 8where the metal component is an alkali metal selected from the groupconsisting of sodium, potassium, lithium, rubidium, cesium and mixturesthereof.
 11. The process of claim 8 where the metal component precursoris selected from the carboxylate, carbonate and hydroxide compound ofthe metal component.
 12. The process of claim 11 where the carboxylateis an acetate compound of the metal component.
 13. The process of claim8 where the shaped article is selected from the group consisting ofextrudes, pills, tablets, spheres and irregular shaped particles. 14.The process of claim 8 where the curing conditions include a temperatureof about ambient to about 200° C. and a time of about 5 minutes to about25 hours.
 15. The process of claim 8 where the activation conditionsinclude a temperature of about 275° C. to about 600° C. and a time ofabout 5 to about 70 minutes.
 16. The process of claim 8 where thealumina, zeolite and an aqueous solution of the metal precursor aremixed and formed into a shaped article.
 17. The process of claim 8 wherethe alumina and zeolite components are formed into a shaped article andthen contacted with an aqueous solution containing a metal precursor.18. The process of claim 8 where alumina powder, zeolite powder andmetal precursor powder are combined and formed into a shaped article.19. A process for removing contaminants from hydrocarbon streamscomprising contacting the stream with a solid shaped adsorbent, atadsorption conditions to remove at least a portion of at least onecontaminant, the adsorbent comprising an alumina component, a zeolitecomponent and an metal component, ), the metal component present in anamount at least 10 mole % of the stoichiometric amount of metal (M)needed to compensate for the negative lattice expressed as the oxidecharge of the zeolite.
 20. The process of claim 19 where the hydrocarbonstream is an olefin stream.
 21. The process of claim 19 where theadsorption conditions include a temperature of about ambient to about80° C. and a pressure of about atmospheric to about 100 atm.
 22. Theprocess of claim 19 where the hydrocarbon stream is a liquid stream andis contacted with the adsorbent at a LHSV of about 0.5 to about 10 hr⁻¹.23. The process of claim 19 where the hydrocarbon stream is a gaseousstream and is contacted with the adsorbent at a GHSV of about 500 toabout 10,000 hr−1.
 24. The process of claim 19 where the contaminantscomprise at least one of CO₂, H₂S, COS, O₂ and CO.
 25. The process ofclaim 19 where the zeolite is selected from the group consisting ofzeolite X, zeolite Y, zeolite A and mixtures thereof.
 26. The process ofclaim 19 where the metal component (Madd) is an alkali metal selectedfrom the group consisting of sodium, potassium, lithium, rubidium,cesium and mixtures thereof.
 27. The process of claim 19 where thezeolite is present in an amount from about 5 to about 55 wt. % of theadsorbent.
 28. The process of claim 19 where the metal component (Madd)is present in an amount from about 0.018 to about 0.08 moles of metal asthe oxide per 100 g of adsorbent.